The present invention relates to the recovery of tungsten values from aqueous alkali metal tungstate solutions by liquid-liquid solvent-extraction process. More particularly, the invention relates to the extraction of tungsten values by an organic mixture and subsequent recovery of an ammonium tungstate solution by stripping.
Prior art processes relating to recovery of tungsten include U.S. Pat. Nos. 3,158,438 to Kurtak; 3,256,058 to Burwell; and 3,293,004 to Musgrove et al; South african patent 684,892 and British patent 1,240,524. U.S. Pat. No. 4,175,109 to Kim relates to a tungsten extraction process.
It is an object of the present invention to provide an improved process for recovery of tungsten values from aqueous alkali metal tungstate solutions.
It is an object of the present invention to improve phase separation during extraction and decrease the concentration of alkali metal in the product ammonium tungstate.
Other and further objects will become apparent from reading the following description.